RARE-EARTH OXYSULFIDE, PROCESS FOR PREPARING THE SAME AND USE THEREOF AS A PHOSPHOR

摘要

The invention relates to a rare earth and / or yttrium oxysulfide which comprises, as an additive, at least one compound distinct from the preceding one and chosen from the group consisting of rare earths and yttrium and which is characterized in that '' it has an oxygen balance or deficit on the surface. The process for preparing the oxysulfide of the invention is characterized in that a rare earth oxysulfide is calcined in the presence of hydrogen, comprising as additive at least one compound distinct from the preceding one and chosen from the group consisting of rare earths and yttrium. The invention also covers a luminescent composition containing an oxysulfide of rare earth and / or of yttrium of the aforementioned type.